Do you know what this is?

I'm trying to recall the website and/or name to a particular method of capturing bolts of electricity in a resin/polymer to be sold as art. I seem to recall that it had some proper name attached to it. I came across it a few years ago and now I'm having the darnedest time recalling or finding it. The electricity would form these beautiful 3D trees in the resin, precisely preserving the look of the bolt from that one instant in time.